Fix Z-order for a bubble when it appears for inactive window.

ui/views/widget/desktop_aura/desktop_window_tree_host.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/base/ui_base_types.h"
@@ skipping 63 matching lines @@
   virtual void CloseNow() = 0;
 
   virtual aura::WindowTreeHost* AsWindowTreeHost() = 0;
 
   virtual void ShowWindowWithState(ui::WindowShowState show_state) = 0;
   virtual void ShowMaximizedWithBounds(const gfx::Rect& restored_bounds) = 0;
 
   virtual bool IsVisible() const = 0;
 
   virtual void SetSize(const gfx::Size& size) = 0;
+  virtual void StackAbove(aura::Window* window) = 0;
   virtual void StackAtTop() = 0;
   virtual void CenterWindow(const gfx::Size& size) = 0;
   virtual void GetWindowPlacement(gfx::Rect* bounds,
                                   ui::WindowShowState* show_state) const = 0;
   virtual gfx::Rect GetWindowBoundsInScreen() const = 0;
   virtual gfx::Rect GetClientAreaBoundsInScreen() const = 0;
   virtual gfx::Rect GetRestoredBounds() const = 0;
 
   virtual gfx::Rect GetWorkAreaBoundsInScreen() const = 0;
 
@@ skipping 63 matching lines @@
   // Returns true if the Widget supports translucency.
   virtual bool IsTranslucentWindowOpacitySupported() const = 0;
 
   // Called when the window's size constraints change.
   virtual void SizeConstraintsChanged() = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_H_